Method and apparatus for cataract surgery

ABSTRACT

A method for performing cataract surgery by slicing or shearing thin layers of cataractous tissue with a surgical probe incorporating a very small diameter tip which performs as a rotary cutter. In one embodiment of the invention, this tip includes a pair of concentric tubes, the outer of which is stationary relative to the inner tube. The inner tube is driven by a miniature motor housed within the probe body. A saline solution conduit and an aspirating vacuum conduit are connected to the robe to supply an irrigating saline solution between the two cutter tips during surgery and an aspirating outlet for cataractous tissue through the bore of the rotating inner tube. The force of the aspirating vacuum is automatically controlled by a plunger which is actuated to close off the vacuum supply to limit any excessive aspiration surge forces which may be created by the reopening of a momentarily plugged tip. This automatic control is necessary to prevent anterior chamber collapse with undesired posterior corneal surface and vitreous face approximation to the probe tip. Several tip-cutter embodiments are shown which are adapted for use in surgical procedures requiring different degrees of cutting safety.

United States Patent 1 Douvas et a1.

[ METHOD AND APPARATUS FOR CATARACT SURGERY [76] Inventors: Nicholas G.Douvas, 4200 N.

Gratiot, Port Huron, Mich. 48050; Henry T. Dinkelkamp, 200 W. ArdardPlace, Prospect, 11]. 60056 [22] Filed: Apr. 25, 1973 [21] Appl. No.:354,376

Related U.S. Application Data [63] Continuation-in-part of Ser, No. 643,Jan. 5, 1970,

abandoned.

[52] U.S. C1. (128/305 [51] Int. Cl A6lb 17/32 [58] Field of Search128/305 [56] References Cited UNITED STATES PATENTS 1,279,495 9/1918 Dom128/305 UX 1,663,761 3/1928 Johnson 128/305 3,589,363 6/1971 Banko eta1.... 128/276 3,614,953 10/1971 Moss .1 128/305 3,618,611 11/1971 Urban128/305 3,712,386 l/l973 Peters 128/305 X 3,732,858 5/1973 Banko 128/305X Primary ExaminerChanning L. Pace Attorney, Agent, or Firm=-Harness,Dickey & Pierce [4 1 May 13,1975

[57] ABSTRACT A method for performing cataract surgery by slicing orshearing thin layers of cataractous tissue with a surgical probeincorporating a very small diameter tip which performs as a rotarycutter. In one embodiment of the invention, this tip includes a pair ofconcentric tubes, the outer of which is stationary relative to the innertube. The inner tube is driven by a miniature motor housed within theprobe body. A saline solution conduit and an aspirating vacuum conduitare connected to the robe to supply an irrigating saline solutionbetween the two cutter tips during surgery and an aspirating outlet forcataractous tissue through the bore of the rotating inner tube. Theforce of the aspirating vacuum is automatically controlled by a plungerwhich is actuated to close off the vacuum supply to limit any excessiveaspiration surge forces which may be created by the reopening of amomentarily plugged tip. This automatic control is necessary to preventanterior chamber collapse with undesired posterior corneal surface andvitreous face approximation to the probe tip. Several tip-cutterembodiments are shown which are adapted for use in surgical proceduresrequiring different degrees of cutting safety.

36 Claims, 26 Drawing Figures PATENIED HAY I 3i975 SHEH 10F 6 mix; mm

INVENTORS Nicholas G. Douvos Henry T. Dinkelkump ATTORNEY PATENIED MY 131975 FIG. 4.

SHEH 2 BF 6 720 I 46 45 h4g 48 52 INVENTORS Nichol d5- G. Douvas HenryTr Dinkelkomp TORNEY FATENTEDW I 3,882,872

SHEH 30? 6 INIVVENTORS Nich olqs G.Douvc1s Henry T Dinkelkclmp ATTORNEYPATENTEB RAY I 3 I975 SHEET BF 6 INZVIENTORS Nicholas 67 Douvos Henry'I', Dinkelkomp ATTORNEY PATENTEU rm 1 arms 3; 882.872 sum 5 OF 6 METHODAND APPARATUS FOR SURGERY CATARAQCT CROSS REFERENCE TO RELATEDAPPLICATION The present application is a continuation-in-part of US.Pat. application Ser. No. 643, filed Jan. 5, 1970, now abandoned, by thesame inventors and entitled Method and Apparatus for Cataract Surgery,"and the entire disclosure of the parent application is incorporatedherein either explicitly or by reference.

BACKGROUND OF THE INVENTION Almost invariably, cataract surgery asperformed in the prior art, has involved a large incision of the sclera.This incision is required to remove adequately the cataractous tissue.As a result of this incision, post operative recovery has beenunnecessarily painful and prolonged. In many instances, the patientmanually massages the eye in order to temporarily relieve thediscomfort. In some instances, the large sutured incision is thusruptured or the eye is functionally harmed.

The large incision has also enhanced the probability of post surgeryinfections which can result in the premanent loss of vision in severecases.

Additionally, with the cost of hospital care increasing steadily, thelong post operative recovery period has placed a high total cost oncataract surgery which could be reduced if a shorter hospitalconvalesence were made medically possible.

Accordingly, the present invention has as its major objectivesminimizing the trauma and recovery time associated with cataract surgeryto the extent that the patent benefits not only medically but alsoeconomically.

DESCRIPTION OF THE PRIOR ART Aspiration of a cataract through a needle(hollow tube) in an effort to minimize the size of surgical incisionprobably dates back to antiquity. Compound needles have recently beenproposed which provide both the irrigating and aspiration functionsusually required to remove cataractous tissue. However, this techniquehas several disadvantages. For example, the surgeon does not havecomplete control of the operation, as an assistant must control the flowof the irrigating solution. Moreover, manipulation of the compoundneedle in the anterior chamber is more limited, and overfilling of thechamber by excessive irrigating pressure may rupture the posteriorcapsule. Current aspirationirrigation techniques can only be used insoft cataractous lens surgery existing in patients under the approximateage of 30. After the age of 30, the lens nucleus becomes sclerotic anddoes not permit removal by aspiration-irrigation technique alone.

A more promising technique and apparatus has been recently introducedwhich has been generally termed an ultrasonic cataract emulsifier. Inthis arrangement, a small incision is made and a flow of artificalaqueous at a predetermined height to give a pressure of 20 mm.

mercury in the eye is allowed to flow between a silicon sleeve and atitanium needle. The titanium needle vibrations (reciprocates) at afrequency of about 40,000 cycles per second. The ultrasonic wavesperform no function in the eye, as the cutting is strictly a contactphenomenum.

The ultrasonic vibrating tip contacts the cataractous lens, and thetissue, which has been irrigated, is aspirated through the bore of thevibrating tip which is connected to a vacuum pump.

When and if the tip becomes plugged by a piece of lens, the pumpcontinues pumping, and the vacuum in the line builds up to help aspiratethat piece of lens into the system. The longer the piece of lens remainson the tip, the higher the vacuum creates in the line.

This is a potentially dangerous system at the precise moment when thetip becomes unplugged, because the cornea can collapse onto the tip andthe vitreous face can also be pulled forwardly. This dangerous potentialis alleviated by the use of a flow meter, and a sensor in the flow meterwhich senses when the flow has dropped to zero (in other words when thetip is occluded). As soon as fiow begins, a solenoid valve vents thesuction line to atmosphere briefly to thus prevent corneal collapse.

SUMMARY OF THE INVENTION The present invention has been used for theremoval .of soft congenital cataracts as well as hard dense calcifiedcongenital cataracts, development cataracts, traumatic cataractsincluding those associated with dense fibrous after-cataract membranes.In many of these cases, vitreous involvement and complications are aforegone conclusion. In these situations, the current aspirationirrigation technique or the ultra-sonic method would not be effective inthe management of dense fibrous aftercataracts, traumatic cataracts, orcalcified posterior polar congenital cataracts. Successful management ofthese cases also requires that a vitrectorny be performed. This isreadily accomplished with the present invention and cannot beaccomplished by the above-mentioned pre-existing techniques. The rotarycutter of this invention generates greater torque and permits the use ofvarious novel tip configurations, thereby providing increased surgicalsafety and versatility.

Additionally, corneal collapse is prevented automatically in oneembodiment of the invention by the use of an integral plunger whichcloses the vacuum or aspirating passages from the vacuum pump when thevacuum exceeds permissible limits. The line also reopens automaticallywhen safe conditions are restored.

An important novel aspect of the invention resides in the provision of athree-tube cutting tip construction. This three-tube tip construction isparticularly advantageous in that itis impossible for vitreous materialto wind on the cutting tip rotor and positive infusion of irrigatingfluid onto the surgical area is always assured. According to a furtheraspect of the invention axial loading on the cutting tip rotor iseliminated and this provides reduced wear and tear on the tip as well asimproved cutting efficiency of the tip cutting edges. Novel tipconfigurations for cutting via shearing action and impacting action arealso disclosed. The invention also permits the use of simplifiedirrigation and aspiration circuits.

The apparatus is greatly simplified over that of the prior art, andtherefore is less costly to produce and maintain.

DETAILED DESCRIPTION OF THE DRAWINGS In order that all of the structuralfeatures for attaining the objects of this invention may be readilyunderstood, reference is herein made to the following drawings wherein:

FIG. 1 shows an overall perspective view of the apparatus with the probeat the left and the operating console at the right;

FIG. 2 is a diagrammatic layout of the apparatus;

FIG. 3 is a front-end view of the probe;

FIG. 4 is a partial sectional view of the probe taken along the line 4-4of FIG. 3;

FIG. 5 is a perspective view of a first embodiment of the probe tip;

FIG. 6 is a perspective view of a second embodiment of the probe tip;

FIG. 7 is a perspective view of a third embodiment of the probe tip;

FIG. 8 is a sectional view of the third embodiment of the probe tiptaken along the line 8-8 of FIG. '7;

FIG. 9 is a sectional view taken along the line 99 of FIG. 4;

FIG. 10 is a perspective view of the surge-control plunger;

FIG. 11 is an enlarged sectional view of the tip and associatedcomponents of the probe;

FIG. 12 is a view of the human eye with the probe tip in the lens;

FIG. 13 is an enlarged view of that portion of the human eye adjacentthe probe tip;

FIG. 14 is a perspective end view of one form of fragmenting type ofcutting tip;

FIG. 15 is a perspective end view of another form of fragmenting typecutting tip;

FIG. 16 is a perspective end view of yet another form of fragmentingtype cutting tip;

FIG. 17 is a longitudinal sectional view through another embodiment ofthe rotary cutter of the present invention;

FIG. 18 is an enlargedsectional view taken along line 18-18 in FIG. 17;

FIG. 19 is an enlarged longitudinal section view of the cutting tip ofFIG. 17;

FIG. 20 is a perspective end view of the rotor of the cutting tip ofFIG. 19;

FIG. 21 is a perspective end view of another form of rotor somewhatsimilar to that of FIG. 20;

FIG. 22 is a perspective end view of another cutting tip for use in thecutter of FIG. 17;

FIG. 23 is a perspective end view of yet another cutting tip for use inthe cutter of FIG. 17;

FIG. 24 is a perspective end view of the rotor of the cutting tip ofFIG. 23;

FIG. 25 is a perspective end view of another form of rotor similar tothe rotor of FIG. 24; and

FIG. 26 is a schematic diagram of irrigation and aspiration circuitswhich may be used with the cutter of FIG. 17.

DESCRIPTION OF THE PREFERRED EMBGDIMENTS In FIGS. 1 and 2, salinesolution of conventional formulation for cataract surgery is stored inthe inverted and elevated flask 10 and is supplied to probe 11 through aflexible conduit 12 which is connected to an inlet port 13 of probe 11through a rigid plastic connector 9 fixed to the probe body by clamp 8.The flask M) is held at a desired elevated position hereafter explainedby an adjustable stand 30. The flow of saline solution may be stopped orrestricted by manually manipulating valve 14 located in the salinesolution conduit 12. Flow of saline solution can also be initiated byelectrically energizing the clamp-type solenoid valve 29 with footswitch 28 to thereby release the clamp and open the saline conduit 12.

Port 16 of probe 11 is coupled to rigid plastic connector 7 and then toflexible vacuum conduit 15 which is routed through a coiled length ofcapillary tubing 18 (FIG. 2) and then through a three-way electricallyoperated solenoid valve 17 (FIG. 2). Solenoid valve 17 selectivelyconnects conduit 15 to atmosphere, or to receiver flask 20 when solenoid17a is energized to actuate plunger 17b to the left to enable spool toconnect conduit 15 to the flask. The receiver flask 20 is connectedthrough a vacuum pressure regulator 19 equipped with a pressure gauge 23to an electrically operated vacuum pump 21 (FIG. 2). Three-way solenoidvalve 17 (FIG. 2) is electrically operated by a foot switch 22.

Probe 11 houses a rotating stepping motor 31 (the details of which areshown in FIG. 4). Electrical power is supplied to this motor throughswitch 33, a DC power supply 34, a fixed oscillator 35, a motor logiccircuit 36 and a plurality of electrical conductors 32. The operatingpanel of console control 37 (FIG. 1) contains a master off-on powerswitch 38, a master saline off-on switch 39, a vacuum pump off-on switch39, a vacuum pump off-on switch 40, a master vacuum off-on switch 41,and a master off-on cutter switch 42. The schematic circuit connectionof these components is shown in FIG. 2, with energizing potential beingapplied to power input terminal 25.

As is shown in the end view of FIG. 3, the body of probe 11 is generallycylindrical about the intersection of the horizontal and vertical centerlines with a protrusion 24 providing a boss for the saline inlet port13.

In FIG. 4, the rotating stepping motor 31 has a hollow shaft 43projecting beyond both ends of the motor housing. A coupling 44 ispermanently fixed to the left end of shaft 43. An adapter 45 is threadedinto cou pling 44. An inner and rotating tube 46 is received by andpermanently fixed to adapter 45. Shaft 43 of the rotating stepping motor31 is generally of a tubular configuration with passageway 47 extendingaxially throughout its entire length.

The left end of shaft 43 is rotatably sealed in the motor housing, andthe right end of shaft 43 engages an O-ring 48 thus providing a seal onthe outside diameter of shaft 43. This same O-ring 48 effects a sealbetween motor end bell 49 and the end face of valve body 50. The outsidediameter of motor 31' is sealed against the inside diameter of probe 11by O-ring 67. Valve body 50 is generally cylindrical in shape with aconcentrically located bore 51. A plunger 52 (FIG. 10) is housed nearthe left end of bore 51. This plunger is closely and slidably fittedinto bore 51. Plunger 52 is urged leftwardly by a helical spring 53which is held in place by an adjusting screw 54 threadably engaged intothe right end of valve body 50.

Two U-shaped crossports 55 intersect bore 51 radially just to the rearof plunger 52. These passageways 55 then connect to the rear counterbore 56 of valve body 50.

A slot 57 extends the entire length of valve body 50 to provide apassageway for the motor energizing conductors 32 and also a groundwire. Plunger body 52 (FIG. 10) has a passageway 58 extending from oneend to the other parallel to but offset from the centerline of theplunger. Plunger S2 is prevented from fully contacting the end of themotor shaft 43 by a small projection 59 which is an integral part of theend face of plunger 52.

An adapter body 60 is also positioned within probe 11. This adapter isgenerally cylindrical body with a passasgeway 61 running axially andconcentrically through its entire length. The right end of passageway 61terminates in port 16, and the left end of passageway 61 connects tocounter bore 56, with an O-ring 62 effecting a seal between the end faceof adapter body 60 and valve body 50. A slot 63 similar to slot 57extends the full length of adapter body 60 to provide a passageway formotor conductors 32. A rubber grommet 64 envelops the motor conductors32 within probe 11 to effect a strain relief for the motor conductors.

The entire motor assembly 31, the valve body 50, and the adapter body 60are keyed together to maintain radial alignment and are compressibly arerigidly held within probe 11 by being trapped between the shoulder 66 ofhousing sleeve 26 and end 68 of the threaded adapter 65.

An outer tube 70 of probe tip 68 is permanently and concentricallyreceived by the central bore of adapter 71. The right end of adapter 71is threadably engaged concentrically into adapter 65. The amount ofengagement of the threads of adapter 71 into adapter 65 is controlled bythree set screws 72a, 72b and 720 (FIG. 3). Once the proper engagementis determined, these three set screws 72a, 72b and 72c can be tightenedequally, thus locking the adapter 71 into adapter 65. An annularpassageway 73 exists between the inside diameter of the outer tube 70and the outside diameter of the rotatable tube 46 (FIG. 11). Salinesolution entering at port 13 is forced to flow through passageway 74,chamber 97 and then through this annular passageway 73.

FIG. 4 shows that inside passageway 75 of rotatable tube 46 communicatesthrough passageway 76 of adapter 45, passageway 47 of motor shaft 43,passageway 58 of plunger 52, double crossports 55, counter bore 56,passageway 61, to the vacuum inlet port 16.

In FIG. 5, a first embodiment of a probe tip 68 with its rotatablecutter is shown. In this version, a generally square or rectangularcutter bar 80 is recessed and permanently fixed radially across the endof the rotatable tube 46. This bar 80 is small enough to provide foursegmented aspiration openings 82 which connect to passageway 75 (FIGS. 1and 11). Likewise, a generally square or rectangular bar section 81 isrecessed and permanently fixed radially across the end of tube 70providing two segmented passageways 83 through which the saline solutioncan flow from the annular openings 73. The objective of thisconfiguration is to provide a shearing or scissors action between thestationary cutter bar 81 and the rotatable cutter bar 80. To effect agood shearing action between these two bars, it is necessary toestablish a very small end clearance which can be adjusted bycontrolling the amount of engagement of the thread on adapter 71.Untreading adapter 71 provides greater clearance, while threading itinto adapter 65 (FIG. 4) reduces the clearance. Once a close clearanceis established between the two cutter bars 80 and 81, adapter 71 can besecured in this position by the three set screws 72a, 11, 0.Accordingly, tip 68 acts as shearing cutter which removes cataractoustissue in thin layers by aspiration and removal through openings 82. Ina preferred embodiment outer tube has a diameter of the order of twomillimeters.

In FIG. 6, a probe tip construction similar to that of FIG. 5 is shown,except the outer tube 70 is curled inwardly at its far end with agenerally square bar 84 being recessed and. permanently affixed radiallyacross the end opening. With end 70a of tube 70 being curled inwardly,the annular passageway 73 is highly restricted at this point and,therefore, a plurality of radial holes 85 are provided in the outer tube70 near its end. These radial holes 85 connect with the annularpassageway 73 through which saline solution will flow. The clearancebetween the bars 80 and 84 can be adjusted in the same manner asdescribed with the probe tip of FIG. 5. The curling of tube 70 at 70aminimizes the chances of injuring non-cataract tissue during surgery,such as the posterior lens capsule. Additionally, the injection ofsaline solution by radial holes 85, which are removed from the cutterbars 80, 84 tends to minimize the tendency for the saline solution toforce the cataractous tissue away from the cutters.

FIGS. 7 and 8 show a third embodiment of a rotatable cutting probe tip.In this version, the end 70b of the outer tube 70 is closed completelyand an end portion 70c of the inside diameter of the tube 70 is reducedso that it fits closely with the outside diameter of the rotatable tube46. Saline solution under pressure from the elevated flask 10 flows fromthe annular passageway 73 through two holes 91 located angularly andradially through the wall section of tube 70 just prior to the area 700where the inside diameter of tube 70 is reduced. Two radial holes arelocated near the end portion 700. A sharp edge 93 exists where these twoholes intersect the reduced bore 94 of the outer tube 70. The end 46a ofrotatable tube is-notched so that only approximately a wall segment ofthe rotatable tube 46 extends to almost the closed end of tube 70adjacent holes 90. Thisend configuration of tube 46 provides a straightline cutting edge 92 as is more clearly shown in FIG. 8. Under thisarrangement, as tube 46 rotates, tissue drawn through the holes 90 issheared off as cutting edge 92 contacts successively the inside edges 93of the holes 90. The vacuum then draws this cut tissue and otherfluids'into passageway 75 by aspiration,

As previously stated, saline solution is supplied to the inlet port 13under the pressure established by the elevation of the flask 10 (FIG.1). This head pressure causes saline solution to flow through passageway74 into the chamber 97 and thence into the annular passageway 73 (FIG.4). From the foregoing description, it is apparent that with the outertube 70 inserted into the anterior chamber of the eye, saline solutionwill flow through passageway 73 and out the appropriate opening in theend of tube 70 into the anterior chamber, whence it will be drawn out ofthe anterior chamber by means of a partial vacuum existing in thepassageway 75. This fluid, along with fragmented cataractous tissue willbe drawn further down the passageway 75 (FIG. 2) and through passageways76, 47, 58, 55, 56, 61 and into the vacuum line 15 through the coiledcapillary restrictor 18, the three-way solenoid valve 17 (whenenergized) and into the evacuated collector bottle 20. The suctioncreated in passageway 75 will also assist in pulling the cataractousmaterial into engagement with the appropriate cutters at the end of thetubes 70 and 46.

To prevent excessive pressure from developing in the anterior chamber,the flask of saline solution is elevated only to a point which willprovide a pressure which can be withstood by the lens. This pressure isof the order of 0.4 psig (20mm water column) which can be obtained byelevating the effective head of the flask 10 approximately 10 in. abovethe probe. The saline solution conduit and passageways are adequatelysized so that with this head pressure an adequate volume (approximately7 ccs per minute) of saline solution will flow from the ports connectedto the annular passageway 73. The flow of saline solution can be startedor stopped by the actuation of the foot switch 28, which in turncontrols a solenoid-operated clamp valve 29 (assuming power switch 38and saline switch 39 are closed). Energization of solenoid 29a releasesthe flow restricting clamp. The flow rate of saline solution can also bethrottled by manually adjusting the screw type clamp valve 14.

In order to provide the maximum force to push or aspirate cataractoustissue into the cutters, it is desirable to have available a high vacuumpressure when the end opening of tube 70 contacts the cataract. In otherwords, the greater this vacuum pressure, the greater will be the forcepushing the cataract material into the end opening of the tube 70 andthus into engagement with the cutters. However, when using a high vacuumsuch as 25 inch mercury column which is approximately 12% psi absolute,it becomes apparent that this vacuum pressure could extract from theanterior chamber a far greater volume of saline solution than can besupplied to the anterior chamber with a head pressure of only one-thirdpsig in the saline solution system. If the vacuum system extracts fluidfrom the anterior chamber faster than the saline solution can besupplied to the anterior chamber, a collapse of the anterior chamber ofthe eye will result.

In order to provide safely the high vacuum pressure and thus the desiredintense force to remove the cataractous tissue, it is necessary torestrict the vacuum system when the end of tube 70 is not contacting thecataract so that it cannot aspirate more saline solution from theanterior chamber than can be supplied by the saline solution system. Ifthis precaution is not observed, it is possible to collapse the anteriorchamber thus undesirably cutting healthy tissue.

There are two methods of achieving this safety restriction in the vacuumsystem (1) provide a small input orifice in the vacuum system at theprobe tip, or (2) increase the length of the vacuum system conduit sothat under free flow conditions the total restriction of the system willnot permit more saline solution to be drawn from the lens capsule thancan be supplied by the saline solution system. It has been found throughcalculation and experimentation that the orifice approach requires anorifice of such a small diameter that it can be easily clogged bycataractous tissue. There fore, a sufficient length of capillary tubing18 having a relatively large ID is used to create this desiredrestriction by increasing the length of the vacuum systems conduit. Withthis coiled length of capillary tubing 18 in the vacuum system, thequantity of saline solution that can be pulled out of the anteriorchamber is limited to an amount less than that supplied by the salinesolution system.

If, however, the outlet saline ports at the end of the tube 70 areblocked such as by pressing them against a brunescens cataractous tissuethe vacuum pressure in the entire system will rise to the maximumpermitted by the regulator 19. If this blockage at the end of tube isthen removed after the vacuum pressure has reached it maximum, therewould exist a high inrush or surge of fluid from the anterior chamberinto the vacuum system due to the accumulator or capacitor effectcreated by the volume of vacuum existing in the conduit and passagewaysof the vacuum system. Such a v surge could quickly extract the smallvolume of fluid existing in the anterior chamber and cause a collapse ofthe anterior chamber. An automatic surge eliminating means is,therefore, provided in this device which consists of plunger 52 and itspassageway 58, the bore 51, the crossports S5, and spring 53.

This surge eliminating means functions as follows: Under low or normalflow, the pressure drop or differential pressure acting upon the endface area 99 (FIG. 10) of the plunger 52 does not create sufficientforce to move the plunger 52 back against the force of spring 53.However, when a surge or high flow is encountered, there exists a highpressure drop or differential pressure acting on end face area 99. Thisdifferential pressure is created by the restriction caused by passageway58 through which the flow must pass to continue through the vacuumsystem. This high differential pressure exerts a sufficient force acrossend face area 99 of slidable plunger 52 to overcome the spring forceexerted by spring 53, and thus moves plunger 52 to a position where itcloses ports 55 or in some instances modulates the degree of closure.With ports 55 closed, the surge is stopped and the pressure on each endof plunger 52 equalizes and the spring force can then return the plunger52 to its normal or forward position. In addition to the differentialpressure moving plunger 52 back to close the ports 55, there exists animpinging force to assist in this movement. This impinging force iscaused by the velocity and mass of the fluid striking end face surface99 of the plunger 52 as the fluid emerges from the nozzle-like passage47. Passageway 58 is positioned off center in plunger 52 to provide asuitable surface 99 to maximize the force of this impingement.

A non-automatic vacuum surge safeguard is also provided. In particular,when foot switch 22 is opened by mometary foot operation, the electricsolenoid valve 17 shuts off the vacuum supply to the probe. That is,solenoid 17a is deenergized enabling anchored spring 17c to pull plunger17b and its connected spool 17d to the right. This action vents conduit15 to atmospheric vent 17e. This foot switch controlled venting is doneto reduce a vacuum surge when the vacuum supply to the probe isexcessive and not adequately controlled by the automatic action ofplunger 52.

DETAILED DESCRIPTION OF THE PREFERRED SURGICAL PROCEDURE The cataractsurgical procedure may be performed under conventional local or generalanesthesia.

An eyelid speculum (not shown) is inserted for eyelid separation. A4"0black silk bridal suture is placed beneath the superior rectus musclefor traction and fixation of globe position, Referring to FIGS. 12 and13, a 3 to 4 mm. conjunctiva] limbus based flap 77 is dissected at 12oclock. The flap is widened to a 6 to 8 mm. width. The flap is dissectedwell forward with scissors so as to expose the surgical limbus '78.Hemostasis is maintained through the conventional use of a lightcautery.

The globe is fixed near the 6 oclock limbus with a forceps and a small 4mm. keratome incision is made through the surgical limbus 78 at 12oclock into the anterior chamber 79. The probe tip of FIGS. 5, 6, 7, 14,15, or 16 is introduced into the anterior chamber 79 through the limbalincision 78 and placed through the anterior lens capsule 86 and into thelens cortex 88. Balanced saline solution is irrigated into the lens 89(by manually closing switches 38, 39 and closing foot switch 28) andanterior chamber 79 from the saline openings in the probe tip 68. Thiscompletes the energizing circuit for solenoid 29a to release solenoidclamp Simultaneous aspiration through the center of the probe tip 68 isaccomplished by vacuum pump 21 by manually closing vacuum pump switch 40and also manually closing master vacuum switch 41 and closing footswitch 22 to connect conduit to flask 20.

Preliminary lens fragmentation is accomplished by coring andhoney-combing the hard lens nucleus with the various end-cutter tipsenumerated above. Final aspiration of tenacious cataractous lenscortical tissue 88 and hard lens nucleus 95 is rendered possible throughthe use of rotary side cutters FIG. 7, FIG. 22, FIG. 19, FIG. 23. Therotary cutting blades in the side-cutting probe tip are activated by theoperating surgeon by manually closing cutter switch 42 and closingcutter foot switch 33. Whenever it is necessary to work close to theiris 96, the rotary cutter is stopped by opening foot switch 33. Thetissue to be extracted is pulled forward and away from the iris orcorneal tissue by means of vacuum traction only. Once the tissue andprobe tip are free of iris and other tissue to be avoided, the rotarycutter is activated by closing the foot switch 33 in order to shred thetissue into particles capable of aspiration.

Throughout the procedure, collapse of anterior chamber 79 is preventedby the hemostatic volumepressure relationship between the irrigatingflow and vacuum aspiration flow. The surge control plunger 52incorporated into the probe handle prevents a surge of aspiration once aplugged probe tip is cleared. Otherwise, an unchecked vacuum aspiratingsurge due to vacuum pressure buildup while the probe tip is temporarilyplugged by a large mass of cataractous material that is being shreddedby the rotary cutter, would lead to anterior chamber collapse withundesired posterior corneal surface and vitreous face approximation tothe probe tip. If necessary due to ineffectiveness of the automaticvacuum control dependent upon plunger 52, an undesirable vacuum surgecan be eliminated by venting the system by operation of master vacuumswitch 41 and/or foot switch 22 to deenergize solenoid 17a to ventconduit 15 to vent 17e. this operation drives solenoid valve 17 into aventing position as previously described.

The side position of the irrigating openings on the probe tip shown inFIGS. 6 and 7 serves to direct the irrigating stream away from the probetip so as to avoid flushing the lens material away from the aspiratingcutting tip. The side position also avoids obstruction by an engagedcataractous mass.

The particular tip embodiment shown in FIG. 7 offers an additionalsafeguard when cutting near posterior lens capsule 98 is involved.

All lens contents involving the central pupillary area down to theposterior lens capsule which may or may not be removed are shredded andaspirated and deposited into collector bottle 20. In many cases of denseposterior capsular opacities, it is necessary to remove the posteriorcapsule. This is combined with the performance of a shallow anteriorvitrectomy in order to prevent the forward migration of vitreous intothe ante rior chamber, where it could give rise to pupillary block andsecondary glaucoma. The presence of vitreous in the anterior chambercould also lead to other complications resulting from vitreous adhesionsto surgical wound and subsequent traction to the iris and/or retina.vitrectomy in the course of the removal of traumatic cataracts whereinvitreous already occupies the anterior chamber, is readily accomplishedwith the present invention.

If preoperative pupillary dilation is inadequate, a sector iridectomymay be incorporated into the technique using a fine No. 30 gauge wirecanula bent into an iris hook and iris scissors.

With adequate pupillary dilation, a normal pupil can be retained with asmall peripheral iridectomy performed at the completion of the cataractextraction. Small peripheral cortical lens remnants left behind underthe iris root do not interfere with the visual result.

The corneoscleral incision is closed with one uninterrupted finecataract suture and the conjunctiva] Tenons flap is closed with eitherinterrupted or running 7 0 catgut suture.

The 4 0 bridal fixation suture is removed. A cataract dressing isapplied and the patient is returned to his room.

In FIGS. 14, 15 and 16 there are disclosed fragmentary perspective viewsof the end construction of three embodiments of an end-core type cuttingtip which may be used with probe 11. These tips are especially useful incoring and fragmenting tissue from underlying attachments either with orwithout simultaneous aspiration and irrigation. Therefore, looking firstat FIG. 14, the first end-core cutting tip comprises an outer tube 112and an inner tube 114 arranged to rotate within outer tube 112. Theforward end of outer tube 112 has a snug fit around inner tube 114 toseal the forward end ofa fluid passage which is provided be tween thetwo tubes. An opening 116 in the side wall of outer tube 112 provides adischarge outlet to the surgical area for irrigating solution whichflows through the fluid passage from probe 11. The forward end of innertube 114 is honed around the outside to a generally conical shape whichtapers radially inwardly in the forward direction as at 118 so that tube114 has a razor sharp cutting edge 120 lying substantially on a circlein a plane perpendicular to the axis of tip 110. Aspiration is effectedthrough the bore of inner tube 114 back to probe 11.

A second end-core cutting tip 122 in FIG. 15 is of generally similarconstruction having outer and inner tubes 124 and 126 respectively and adischarge opening 128 for the irrigating fluid passage between thetubes. Aspiration is via the bore of inner tube 126. The forward end ofinner tube 126 is also conically honed as at 130, but a plurality ofcircumferentially spaced axial serrations 132 are provided around theforward end of the tube. thus, the cutting edge of tube 126 is notcircumferentially continuous as was edge 120 of tip 110, but ratherinner tube 126 has a plurality of individual arcuate razor sharp cuttingedges 134 lying substantially on a circle perpendicular to the tip axis.

A third end-core cutting tip 136 in FIG. 16 is of generally similarconstruction having an outer tube 138, inner tube 140 and a dischargeoutlet 142 for the fluid passage between the tubes. The forward end ofinner tube 126 is also conically honed as at 144. A pair ofdiametrically opposed rectangular slots 146, extend axially rearwardlyfrom the forward end of tube 140.1n this way tube 140 has a pair ofdiametrically opposed, arcuately extending, razor sharp cutting edges148 lying substantially on a circle perpendicular to the tip axis.Aspiration is via the bore of inner tube 140.

As mentioned before, the particular advantage of the end-core typecutting tip resides in its coring and fragmenting capability. With theend-core tip of the present invention such coring and fragmenting isgreatly facilitated and represents a notable improvement in surgicalprocedures. Thus by virtue of the present invention, calfified orfibrous plaques of lens opacity can be fragmented, and aspirated as candense, rigid, congenital posterior polar cataract, membranous traumaticaftercataract and senile brunescent nuclear cataract. The cutting tipsof FIGS. 14, and 16 do not possess the shearing type cutting action ofthe earlier described tips in the earlier drawing figures; rather tips110, 122 and 136 exhibit cutting action, which results in fragmentationand coring of tissue, when the rotating rotor is pressed slightly intothe tissue. Cutting can be done with or without simultaneous aspirationand irrigation according to the desire of the surgeon performing theprocedure. By initially using any of the end-core tips in a surgicalprocedure, large masses of tissue can be efficiently broken apart andsucked up by the cutting instrument. As a result the invention canprovide improved efficiency by reducing overall surgical time, whilesimultaneously, because of its improved cutting action, minimizing oreliminating the risk of injury ot adjacent tissue which is notintendedto be removed.

The invention further provides a second embodiment of cuttinginstrument, or probe, disclosed in FIG. 17, and identified by thenumeral 150. Cutting instrument 150 comprises a generally tubular motorhousing 152 and a generally tubular spindle body 154 threaded onto theforward end of housing 152 as at 156. A 12 volt DC permanent magnetmotor 158 is contained within housing 152, and a gear head 160 ismounted onto the axially forward end of motor 158. The forward end ofmotor 158 is telescopically inserted into the open rear end of the gearhead housing. A tubular shell 164 is telescopically inserted over therear end of motor 158 to enclose the terminal conductor construction viawhich electricity is conducted to motor 158. A pair of spring-loadedelectrical terminals 166, 168 extend through the rear of shell 164 andare biased into engagement with suitable electrical connections in anend plug 170 which is threaded into the open rear end of housing 152 asat 172. A cable 174 containing positive, negative and ground wires leadsfrom plug 170 to a three terminal connector 176 which is adapted to beconnected to a source of 12 volt DC power for energizing motor 158. Thediametrically reduced forward end of gear head 160 fits within acorrespondingly diametrically-reduced forward portion of the bore ofhousing 152. An annular anti slip disk 178 is fitted over thisdiametrically-reduced portion of gear head 160. The

annular forwardly facing shoulder of gear head bears against theshoulder 179 within the bore of housing 152 through anti-slip disk 178.The axial force with which gear head 160 bears against shoulder 179 isdetermined by the compression of the springs associated with terminals166, 168 when end plug is threaded onto body 152. The frictional contactprovided by disk 178 between gear head 160 and shoulder 179 preventsmotor 158 from angularly slipping within the bore of housing 152 whenmotor torque is developed. A drive shaft 180 having an open diametricalslot 182 at the forward end thereof protrudes from the diametricallyreduced forward portion of gear head 160. When electric power is appliedvia connector 176 through terminals 166, 168 to motor 158, shaft 180rotates. The speed of shaft 180 is equal to the speed of motor 158divided by the gear ratio of gear head 160. Gear reduction of 6.3 to land 11.8 to 1 have been found to provide suitable ranges of cuttingspeeds when used in conjunction with motor 158 having a maximum speed of11,000 rpm. (Without a gear head up to 11,000 rpm can be obtained.) Itwill be appreciated that that optimum cutting speed will depend upon thecutter tip construction and the nature of the surgery. The speed may bevaried according to well-known techniques by varying the percentage ofvoltage applied to the motor.

A drive shaft 184 is journalled for rotation within spindle body 154 viaa pair of axially spaced glass filled Teflon bearings 186 and 188. Therear end of shaft 184 is operatively coupled for rotation with shaft 180via a novel axial lost motion coupling which will be explained later ingreater detail. Bearings 186 and 188 are inserted into opposite ends ofdiametrically reduced bore segments 190, 192 which are separated by afurther diametrically reduced bore segment 194. A coil spring 196 isdisposed around the portion of shaft 184 within bore portion 194. Spring196 bears against washers 198 and 200 which are arranged within boresegments and 192 respectively so that washer 198 compresses an annularseal 202 between itself and bearing 186 and washer 200 compresses anannular seal 204 between itself and bearing 188 to thereby seal the endsof bore segment 194. Bearings 186 and 188 are retained axially in theillustrated position with their respective lips bearing againstshoulders at the ends of bore segments 190 and 192. Retention iseffected by means of a tubular adapter body 212 which is inserted overand affixed to the end of shaft 184 which protrudes forwardly throughbearing 186, and a tubular coupling 226 which is threaded onto the rearend of shaft 184 as as at 234. Coupling 226 is threaded onto shaft 184an amount sufficient to draw adapter 212 against bearing 186 and itself(i.e. coupling 226) against bearing 188 whereby adapter body 212 andcoupling 226 retain bearings 186 and 188 in the illustrated position.

A tubular conduit 206 is inserted into an inclined bore in the side wallof body 154 to intercept bore segment 194. A passage 208 extendsrearwardly through shaft 184 from the forward end thereof and terminatesat a hole 210 in the side wall of shaft 184. Hole 210 opens to theaxially sealed annular space 207 around shaft 184 within bore segment194. The adapter 246 of a cutting tip assembly 216 is threaded onto theforward end of adapter body 212 as at 214. Thus a passage is providedfrom tube 206 through space 207, hole 210, passage 208 and coupling 226to adapter 212. As will be seen in greater detail hereinafter,aspirating suction is applied to this passage and thence through tip 216to the cutting area thereof.

An end cap 218 is threaded onto the forward end of spindle body 154 asat 219. Cap 218 and the forward end of body 154 are arranged relative toadapter body 212 such that an axially extending free space 221 isprovided around adapter body 212 within the instrument. An inlet tube220 is inserted into an inclined bore in body 154 to intercept space221. As will be seen in greater detail hereinafter, irrigating fluid isintroduced via tube 220, through space 221 and a passage in tip assembly216 for dispensingirrigating fluid onto the surgical area. The portionof tip assembly 216 forward of adapter 246 extends through the bore ofend cap 218 and is retained by means of a collet nut 222 which isinserted over the forward end of tip assembly 216 and threaded onto theforward end of end cap 218 as at 223. A gasket 224 seals the bore of endcap 218 around tip 216. A clip 239 for retaining flexible conduits totubes 206 and 220 is provided around housing 152.

The coupling arrangement between shaft 180 and shaft 184 provides anaxial lost motion connection whereby axial forces from shaft 180 are nottransmitted through to the cutting tip 216, and the motor and gear headcan be readily assembled and replaced if necessary. Details of thiscoupling can be seen in FIGS. 17 and 18. A pair of diametrically opposedaxial slots 228 in coupling 226 extend forwardly from the rear endthereof. A key 229 extends diametrically across the rear end of coupling226 with the ends of key 229 received in slots 228. The key is suitablyshaped so that it cannot be substantially displaced radially of thecoupling. An annular retaining ring 232 around coupling 226 axiallyretains key 229 in slots 228. A coupling spring 233 is disposed withincoupling 226 and bears against the rear end of shaft 184 and the centralportion of key 229 thereby biasing key 229 axially rearwardly againstring 232. When end plug 170 is being threaded onto spindle body 154, themotor and gear head are urged axially forwardly so that shaft 180 fitsinto the bore of coupling 226 and slot 182 engages the central portionof key 229. This provides an axial lost motion connection with key 229being displaced axially forwardly of coupling 226 against the bias ofspring 233 an amount sufficient to accommodate the motor and gear head.Furthermore in the assembled instrument any axial loading on shaft 184by shaft 180 is cushioned by spring 233.

The details of cutting tip assembly 216 are illustrated in FIG. 19.Cutting tip assembly 216 represents one form of tip which may be usedwith either of the above instruments. The assembly 216 comprises anouter stator tube 240, an inner stator tube 242, a rotor tube 244 andadapter 246 which is affixed to the rear end of rotor tube 244 forconnection to coupling body 212. Inner stator tube 242 extendscompletely through outer stator tube 240. The axial ends of outer statortube 240 are shaped to fit snugly around the outside of inner statortube 242. The rear end of tube 240 may be silver soldred to tube 242 asshown to preclude any relative rotation between the tubes. The relativesizes of tubes 240 and 242 are such that an annular axially extendingfluid passage 246 is provided between the two stator tubes. One or moreinlet openings 248 are provided in outer stator tube 240 at the rear endthereof and one or more discharge opening 250 are provided in tube 240at the forward end thereof. As illustrated the openings may be ofcircular shape and may face generally radially outwardly. Openings 248are open to space 221 so that the irrigating fluid which entersinstrumenet via tube 220 can flow through space 221, openings 248, alongpassage 246 and out via openings 250 onto the surgical area. The forwardend of inner stator tube 242 which projects forwardly from the forwardend of outer stator tube 240 comprises a circular opening 252 in itsside wall which opening defines a sharp cutting edge 254. The forwardend of tube 242 is closed by an end wall 256 which may be in the form ofa plug inserted into and affixed to the side wall of the tube. (Note:This construction is not illustrated in the drawing.) According to oneof the important features of the invention the side wall of tube 242 issolid and thus rotor 244 is shielded at openings 250. Rotor 244comprises a cut-away opening 258 at the forward end thereof which leavesan axially extending arcuately cross-sectioned finger 260 extending fromthe annular cross-sectioned tubular portion constituting the remainderof rotor 244. The shape of finger 260 is such that razor sharp straightaxial cutting edges 262 are provided along the axial edges of fingerparallel to the tip axis. When rotor 244 rotates within tube 242 theleading cutting edge 262 cooperates with cutting edge 254 of the innerstator tube to shear tissue. Note that the forward end of finger 260 isspaced slightly from end wall 256. Since axial loading on rotor 244 issubstantially eliminated by the construction of instrument 150, there isno possibility of the axially forward end of rotor 244 grinding into endwall 256. The only interaction between rotor 244 and inner stator tube242 is the rotational contact between the side walls thereof. Thus,because of this aspect of the invention, the cutting tips can lastlonger and the possibility of material (such as minute metal flakes)being ground away from end wall 256 and/or the forward end of finger 260is eliminated. This is especially important for eye surgery when suchminute metal particles could possibly escape into the eye of thepatient. Rotor 244 extends through the rear end of tube 242 and asealing coupling 266 seals the open rear end of inner tube 242 to rotor244. Coupling 266 may be heat shrunk onto the tubes to provide a fluidseal which permits rotor 244 to rotate within tube 242. The rear end ofrotor 244 fits within a bore in adapter 246. The bore 264 of rotor 244is thereby open to passage 208. Aspirating suction which entersinstrument 150 via tube 206 is transmitted through passage 208, and bore264, to the forward end of the tip assembly. With suction applied totube 206 excess irrigating fluid as well as cut tissue pieces can besucked through opening 252 along bore 264 and passage 208 back fordischarge via tube 206. When motor 158 is energized, the rotation ofshaft is transmitted via coupling 226, shaft 184 and adapter body 212 toturn adapter 246 and hence rotor 244. The stator structure of the tip isconstrained against rotation by collet nut 222.

' FIG. 22 illustrates a fragmentary perspective view of the forward endof another form of cutting tip construction wherein similar componentsfrom FIG. 19 are identified by like numerals. The tip of FIG. 22 differsfrom the tip of FIG. 19 in that opening 252 in inner stator tube 242 ofFIG. 22 is of generally rectangular shape. The opening 252 of FIG. 22lies in a plane which extends axially of the tip intercepting both endwall 256 and the side wall of the inner stator tube. Cutting edges 254extend along the sides and front of the opening. The side edges arestraight axial edges parallel to the tip axis. The rotor 244 of FIG. 22has a pair of diametrically opposed fingers 260 instead of the singlefinger 260 in FIG. 19. The cutting tips of FIGS. 19 and 22 are termedprotected side cutters". It is necessary to apply aspirating suction tothese tips to suck tissue into openings 252 for subsequent cutting.

FIG. 23 discloses yet another form of tip wherein like components of thepreceding figures are identified by like numerals. The cutting tip ofFIG. 23 has its opening 252 lying in a plane which is at an acute anglerelative to the axis of the tip. The plane intercepts both the end walland side wall of the inner stator tube and thus defines a generallyelliptical contour in the side wall and a straight transverse segment inthe front end wall. The cutting edge 254 also has correspondingelliptical and straight contoured sections. This cutting tip is termedon exposed side cutter. It can perform some cutting without thenecessity of accompanying aspirating suction.

As mentioned earlier one advantage of cutting tip 216 is that rotor 244is shielded from exposure to the outside at openings 250 by the adjacentwall of the inner stator tube. Another advantage of this three tube tipconstruction is that sealing between the rotor and the stator structureis not nearly as critical as in the two tube tips. In the earlier twotube tips having a rotor tube and only a single stator tube, not onlymust the forward end of the stator tube have a sufficiently snug fitwith the wall of the rotor tube to prevent fluid from short circuiting"into the rotor aspiration bore without flushing the surgical area butalso it must at the same time permit the rotor to turn without unduerestriction. With the three tube construction, the possibility of afluid short circuit is eliminated. This is because the inner and outerstator tubes which define the fluid passage for the irrigating fluid arenot rotating with respect to each other. Therefore, the seal of theforward end of the outer tube around the inner tube can be made tightand leakproof. Thus when irrigating fluid is discharged via the outletopenings 250, flow of fluid onto the surgical area is always assured.Also because the inner stator tube shields rotor 244 at openings 250,tissue adjacent the immediate surgical area are being cut at opening 252which might enter opening 250 cannot be caught by the rotor finger andwound around the rotating rotor. This is especially important incataract removal where it is often desired to perform a shallow anteriorvitrectomy without wrapping uncut vitreous on the rotor through theirrigation port.

FIGS. and 21 illustrate two other forms of single finger rotor similarto that in FIG. 19. Like numerals from FIG. 19 are retained to identifylike elements in FIGS. 20 and 21. Like the rotor of FIG. 19, the rotorfinger 260 in FIG. 20 has a curved radially outer surface 260a matchingthe curvature of the inner wall of inner stator tube. However, the innersurface 260b of the rotor finger in FIG. 20 is flat while thecorresponding surface of the rotor finger of FIG. 19 is curved. In FIG.21 the rotor finger has a greater arcuate extent about the axis of thetube. The forward end of the rotor finger has an end wall 260C acrossthe forward end of the finger. The cutting edge 262 does not extend thefull length of the finger; rather the cutting edge is provided bybeveling the forward edge portion of the finger inwardly so that thecutting edge extends axially rearwardly from the forward end of thefinger only a fraction of the total length of the finger. The edge atthe end wall is similarly inwardly beveled to provide a transversecutting edge 262a connecting the two axial cutting edges 262. In orderto optimize the cooperative shearing and cutting action of the rotor andstator cutting edges, the entire portion of finger 260 which is axiallycoextensive with opening 252 can be made to bear against the inner wallof inner stator tube 242, for example, in the following fashion. Eachrotor finger is first bent and next the forward ends of the rotorcutting edges are flared outwardly such that the rotor cutting edgesbear against the inner wall of inner stator tube 242 at least as farrearwardly as the rear end of the opening 252. In this way the rotorcutting edges have an extremely close approximation to the inner wall oftube 242 and optimum cutting action is attained when rotor 244 turns.

FIGS. 24 and 25 illustrate two forms of two finger rotors. Like numeralsfrom the earlier figures are retained to identify like elements in FIGS.24 and 25. The rotor of FIG. 24 is used in the cutting tips of FIG. 23and FIG. 22. In their free states fingers 260 extend radially outwardlyin the forward direction at a small acute angle to the axis of therotor. With the rotor inserted into the inner stator tube, the fingersbear against the tube side wall, and this results in improved cuttingaction when the tip is used. In the tip of FIG. 25 the outer surface ofthe forward ends of the fingers are honed at 260d to a circularcross-section which matches that of the inner wall of the inner statortube. In this way, the contact of the fingers with the inner stator tubewall is distributed along a portion of the axial lengths of the innerstator tube wall and of the fingers. This is in contrast to the rotor ofFIG. 24 which at least theoretically would have only an arcuate edgecontact of each finger with the inner stator tube wall; however, it ispreferred to shape the fingers in FIG. 24 as described above in FIGS. 20and 21 to provide optimum cutting and shearing action.

FIG. 26 illustrates simplified aspirating suction systems for use withprobe 150. A syringe S connects to tube 206 while tube 220 connectsthrough a valve V to a pair of fluid dispensing containers B1 and B2disposed at different vertical levels. Containers B1 and B2 are arrangedto provide gravity feed of irrigating fluid to probe 150. In oneposition valve V permits flow from only container B1, and this providesa limited flow of fluid onto the surgical area. When valve V is inanother position, flow is from only container B2; this providesincreased flow since container B2 is at a higher level. Possible flow tocontainer B1 from container B2 is blocked by valve V. Valve may becontrolled by the surgeon or his assisting personnel. Syringe S can beoperated by assisting personnel at the command of the surgeon to provideaspirating suction for removing fluid and/or cut tissue. An importantadvantage of using syrings S is that in critical areas, for exampleclose to the retina or iris, the amount of suction can be preciselycontrolled by the assisting personnel and if need be pressure can beapplied via syringe S to discharge any material which may have beendrawn into the tip via previous aspirating suction from syringe S.

The present invention makes an important and noteworthy contribution tothe surgical art, and in particular to eye surgery where extremely closeprecision is required in relatively dimensionally limited areas. Withthe instruments, the cutting tips and the method of the invention, thesurgeon can perform difficult, intricate surgical procedures withincreased safety to the patient and usually with a minimum of surgicaltime. It will also be appreciated that the apparatus of the inventionprovides the surgeon with a high degree of versatility in that variouscombinations of the disclosed rotor and stator structures are possiblein a single cutting tip assembly. Furthermore, the various tipconstructions may be used with either type of disclosed probe.

It is to be understood that the foregoing description is that of apreferred embodiment of the invention. Various changes and modificationsmay be made without departing from the spirit and scope of the inventionas defined by the appended claims.

We claim:

1. An axially-extending cutting tip for a surgical instrument having abody and a rotary shaft mounted on said body, said cutting tipcomprising a stator tube, an opening in the side wall of said statortube defining a generally axially extending sharp cutting edge, and arotor within said stator tube comprising at least one axially extendingfinger at the forward end thereof, a generally axially extending sharpcutting edge on said finger cooperative with the cutting edge of saidstator tube when said rotor rotates within said stator tube, said fingerbeing constrained by said stator tube to bias said finger cutting edgeagainst the side wall of said stator tube.

2. The cutting tip of claim 1 wherein said finger hasan arcuate crosssection.

3. The cutting tip of claim 2 wherein the cutting edge on said fingerextends axially parallel to the tip axis.

4. The cutting tip of claim 3 wherein the cutting edge on said finger isfashioned at the outer edge of an inwardly directed bevel on saidfinger.

5. The cutting tip of claim 2 including an end wall at the forward endof said finger.

6. The cutting tip of claim 5 including a cutting edge on said end wall.

7. The cutting tip of claim 1 wherein said stator tube has an end wallat the forward end thereof and the forward end of said finger is spacedrearwardly of said end wall.

8. A cutting tip for a surgical instrument, said cutting tip comprising:a stator tube having a side wall the inside of which is of cylindricalshape; an opening in said stator tube intercepting at least said sidewall and defining on said side wall a sharp cutting edge; a rotorelement within said stator tube, said rotor element comprising a bodyhaving a cylindrical outer wall snugly journaling said rotor elementwithin said stator tube and a finger extending forwardly of said body,said finger comprising a sharp cutting edge cooperable with said cuttingedge on said stator tube side wall; said rotor element, whenunconstrained by said stator tube, having a portion of said fingerthereof disposed outside of an imaginary cylindrical surface defined bya forward continuation of the cylindrical outer wall of said rotor body;said rotor element, when constrained within said stator tube, biasingsaid finger thereof against the inside of said stator tube side wall.

9. A cutting tip as claimed in claim 8 wherein said finger is inclinedradially outwardly and axially forwardly of said rotor body when saidrotor element is unconstrained and is substantially parallel to thecutting tip axis when said rotor element is constrained within saidstator tube.

10. A cutting tip as claimed in claim 9 wherein said finger has aradially outer surface at least a portion of which bears against theinside of said rotor tube side wall and has a curvature substantiallymatching the curvature of the inside of said stator tube side wall.

11. A cutting tip as claimed in claim 10 wherein said finger has axiallyextending sides and said cutting edge on said finger is fashioned on oneof said finger sides.

12. A cutting tip as claimed in claim 11 wherein said finger furtherincludes an additional cutting edge fashion on the other of said fingersides.

13. A cutting tip as claimed in claim 12 wherein said finger cuttingedges are biased against the inside of said stator tube side wall.

14. A cutting tip as claimed in claim 13 wherein said finger cuttingedges are substantially parallel to the axis of the cutting tip whensaid rotor element is constrained within said stator tube. I

15. A cutting tip as claimed in claimv 8 wherein said stator tube has atransverse end wall at the forward end thereof and the forward end ofsaid finger is spaced rearwardly of said stator tube end wall.

16. A cutting tip as claimed in claim 8 wherein said finger cutting edgeis biased against the inside of said stator tube side wall.

17. A cutting tip as claimed in claim 8 wherein said finger is ofarcuate transverse cross section having circumferentially spaced fingerside edges and said cutting edge on said finger is fashioned on one ofsaid finger side edges.

18. A cutting tip as claimed in claim 17 wherein said finger, whenunconstrained, has said one finger side edge flared outwardly biasingsaid finger cutting edge against the inside of said stator tube sidewall.

19. A cutting tip as claimed in claim 18 wherein said finger has anadditional cutting edge extending along the other of said finger sideedges and biased against the inside of said stator tube side wall.

20. A cutting tip as claimed in claim 19 wherein said finger cuttingedges are straight.

21. A cutting tip as claimed in claim 19 wherein said finger cuttingedges are parallel to the cutting tip axis.

22. A cutting tip as claimed in claim 8 wherein said finger has aradially outer surface, the forward end of which is contoured to matchthe contour of the inside of the stator tube side wall and whichcontoured forward end is biased against the inside of said stator tubeside wall.

23. A cutting tip as claimed in claim 22 wherein said finger cuttingedge extends axially along a side edge of the radially outer surface ofsaid finger.

24. A cutting tip for a surgical instrument, said cutting tipcomprising: a stator tube having a side wall the inside of which is ofcylindrical shape; an opening in said stator tube intercepting at leastsaid side wall and defining on said side wall a sharp cutting edge; arotor element within said stator tube, said rotor element comprising abody having a cylindrical outer wall snugly journaling said rotorelement Within said stator tube and a finger extending forwardly of saidbody, said finger comprising a sharp cutting edge cooperable with saidcutting edge on said stator tube side wall; said rotor element, whenunconstrained by said stator tube, having a portion of said fingerthereof disposed outside of an imaginary cylindrical surface defined bya forward continuation of the cylindrical outer wall of said rotor body;said rotor element, when constrained within said stator tube, biasingsaid finger cutting edge against the inside of said stator tube sidewall.

25. A cutting tip as claimemd in claim 24 wherein said finger isinclined radially outwardly and axially forwardly of said rotor bodywhen said rotor element is unconstrained and is substantially parallelto the cutting tip axis when said rotor element is constrained withinsaid stator tube.

26. A cutting tip as claimed in claim 25 wherein said finger has aradially outer surface at least a portion of which is biased against theinside of said stator tube side wall and has a curvature substantiallymatching the curvature of the inside of said stator tube side wall.

27. A cutting tip as claimed in claim 26 wherein said finger has axiallyextending sides and said cutting edge on said finger is fashioned on oneof said finger sides.

28. A cutting tip as claimed in claim 27 wherein said finger furtherincludes an additional cutting edge fashioned on the other of saidfinger sides and biased against the inside of said stator tube sidewall.

29. A cutting tip as claimed in claim 24 wherein said finger is ofarcuate transverse cross section having circumferentially spaced fingerside edges and said cutting edge on said finger is fashioned on one ofsaid finger side edges. I

30. A cutting tip as claimed in claim 29 wherein said finger has saidone finger side edge flared outwardly to cause said finger cutting edgeto be biased against the inside of said stator tube side wall.

31. A cutting tip as claimed in claim 30 including an additional cuttingedge extending along the other of said finger side edges and biasedagainst the inside of said stator tube side wall.

32. A cutting tip as claimed in claim 31 wherein said finger cuttingedges are straight.

33. A cutting tip as claimed in claim 31 wherein said finger cuttingedges are parallel to the cutting tip axis.

34. A cutting tip as claimed in claim 1 wherein said rotor includes afluid passage therethrough.

35. A cutting tip as claimed in claim 8 wherein said rotor body includesa fluid passage therethrough.

36. A cutting tip as claimed in claim 24 wherein said rotor bodyincludes a fluid passage therethrough.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,882,872 DATED May 13, 1975 1NVENTOR S Nicholas G. Douvas and Henry T.Dinkelkamp It is certified that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:Address Henry T. Dinkelkamp, "Ardard' should be Orchard-.

Abstract, line 10, "robe" should be -probe-,

Column 1, line 25, "premanent" should be -permanent--', Column 1, lines33 and 34, "patent" should be --patient-, Column 1, line 66,"phenomenum" should be phenomenon-. Column 4, line 25, delete "a vacuumpump off-on switch 39, Column 5, line 18, "are" (second occurrence)should be --and-. Column 5, line 60, "Untreading" should be--Unthreading-. Column 11, line 21, "calfified" should be calcified-.

Column 11, line 40, "0t" should be --to-.

Column 14, line 21, "annular" should be --annularly-.

Column 15, line 20, "on" should be -an-.

Column 15, line 46, delete "are".

Claim 10, line 3, (Column 18, line 5), "rotor" should be --stator-.Claim 12, line 3, "fashion should be --fashioned--,

Claim 25, line 1, "claimemd" should be --claimed--.

Signed and Sealed this [SEAL] Seventh D of o ctorberl975 A nest:

RUTH C. MASON Arresting Officer C. MARSHALL DANN (ummissl'mrer oflarenlsand Trademarks

1. An axially-extending cutting tip for a surgical instrument having abody and a rotary shaft mounted on said body, said cutting tipcomprising a stator tube, an opening in the side wall of said statortube defining a generally axially extending sharp cutting edge, and arotor within said stator tube comprising at least one axially extendingfinger at the forward end thereof, a generally axially extending sharpcutting edge on said finger cooperative with the cutting edge of saidstator tube when said rotor rotates within said stator tube, said fingerbeing constrained by said stator tube to bias said finger cutting edgeagainst the side wall of said stator tube.
 2. The cutting tip of claim 1wherein said finger has an arcuate cross section.
 3. The cutting tip ofclaim 2 wherein the cutting edge on said finger extends axially parallelto the tip axis.
 4. The cutting tip of claim 3 wherein the cutting edgeon said finger is fashioned at the outer edge of an inwardly directedbevel on said finger.
 5. The cutting tip of claim 2 including an endwall at the forward end of said finger.
 6. The cutting tip of claim 5including a cutting edge on said end wall.
 7. The cutting tip of claim 1wherein said stator tube has an end wall at the forward end thereof andthe forward end of said finger is spaced rearwardly of said end wall. 8.A cutting tip for a surgical instrument, said cutting tip comprising: astator tube having a side wall the inside of which is of cylindricalshape; an opening in said stator tube intercepting at least sAid sidewall and defining on said side wall a sharp cutting edge; a rotorelement within said stator tube, said rotor element comprising a bodyhaving a cylindrical outer wall snugly journaling said rotor elementwithin said stator tube and a finger extending forwardly of said body,said finger comprising a sharp cutting edge cooperable with said cuttingedge on said stator tube side wall; said rotor element, whenunconstrained by said stator tube, having a portion of said fingerthereof disposed outside of an imaginary cylindrical surface defined bya forward continuation of the cylindrical outer wall of said rotor body;said rotor element, when constrained within said stator tube, biasingsaid finger thereof against the inside of said stator tube side wall. 9.A cutting tip as claimed in claim 8 wherein said finger is inclinedradially outwardly and axially forwardly of said rotor body when saidrotor element is unconstrained and is substantially parallel to thecutting tip axis when said rotor element is constrained within saidstator tube.
 10. A cutting tip as claimed in claim 9 wherein said fingerhas a radially outer surface at least a portion of which bears againstthe inside of said rotor tube side wall and has a curvaturesubstantially matching the curvature of the inside of said stator tubeside wall.
 11. A cutting tip as claimed in claim 10 wherein said fingerhas axially extending sides and said cutting edge on said finger isfashioned on one of said finger sides.
 12. A cutting tip as claimed inclaim 11 wherein said finger further includes an additional cutting edgefashion on the other of said finger sides.
 13. A cutting tip as claimedin claim 12 wherein said finger cutting edges are biased against theinside of said stator tube side wall.
 14. A cutting tip as claimed inclaim 13 wherein said finger cutting edges are substantially parallel tothe axis of the cutting tip when said rotor element is constrainedwithin said stator tube.
 15. A cutting tip as claimed in claim 8 whereinsaid stator tube has a transverse end wall at the forward end thereofand the forward end of said finger is spaced rearwardly of said statortube end wall.
 16. A cutting tip as claimed in claim 8 wherein saidfinger cutting edge is biased against the inside of said stator tubeside wall.
 17. A cutting tip as claimed in claim 8 wherein said fingeris of arcuate transverse cross section having circumferentially spacedfinger side edges and said cutting edge on said finger is fashioned onone of said finger side edges.
 18. A cutting tip as claimed in claim 17wherein said finger, when unconstrained, has said one finger side edgeflared outwardly biasing said finger cutting edge against the inside ofsaid stator tube side wall.
 19. A cutting tip as claimed in claim 18wherein said finger has an additional cutting edge extending along theother of said finger side edges and biased against the inside of saidstator tube side wall.
 20. A cutting tip as claimed in claim 19 whereinsaid finger cutting edges are straight.
 21. A cutting tip as claimed inclaim 19 wherein said finger cutting edges are parallel to the cuttingtip axis.
 22. A cutting tip as claimed in claim 8 wherein said fingerhas a radially outer surface, the forward end of which is contoured tomatch the contour of the inside of the stator tube side wall and whichcontoured forward end is biased against the inside of said stator tubeside wall.
 23. A cutting tip as claimed in claim 22 wherein said fingercutting edge extends axially along a side edge of the radially outersurface of said finger.
 24. A cutting tip for a surgical instrument,said cutting tip comprising: a stator tube having a side wall the insideof which is of cylindrical shape; an opening in said stator tubeintercepting at least said side wall and defining on said side wall asharp cutting edge; a rotor element within said stator tube, said rotorelement comprising a body having a cylindrical outer wall sNuglyjournaling said rotor element within said stator tube and a fingerextending forwardly of said body, said finger comprising a sharp cuttingedge cooperable with said cutting edge on said stator tube side wall;said rotor element, when unconstrained by said stator tube, having aportion of said finger thereof disposed outside of an imaginarycylindrical surface defined by a forward continuation of the cylindricalouter wall of said rotor body; said rotor element, when constrainedwithin said stator tube, biasing said finger cutting edge against theinside of said stator tube side wall.
 25. A cutting tip as claimemd inclaim 24 wherein said finger is inclined radially outwardly and axiallyforwardly of said rotor body when said rotor element is unconstrainedand is substantially parallel to the cutting tip axis when said rotorelement is constrained within said stator tube.
 26. A cutting tip asclaimed in claim 25 wherein said finger has a radially outer surface atleast a portion of which is biased against the inside of said statortube side wall and has a curvature substantially matching the curvatureof the inside of said stator tube side wall.
 27. A cutting tip asclaimed in claim 26 wherein said finger has axially extending sides andsaid cutting edge on said finger is fashioned on one of said fingersides.
 28. A cutting tip as claimed in claim 27 wherein said fingerfurther includes an additional cutting edge fashioned on the other ofsaid finger sides and biased against the inside of said stator tube sidewall.
 29. A cutting tip as claimed in claim 24 wherein said finger is ofarcuate transverse cross section having circumferentially spaced fingerside edges and said cutting edge on said finger is fashioned on one ofsaid finger side edges.
 30. A cutting tip as claimed in claim 29 whereinsaid finger has said one finger side edge flared outwardly to cause saidfinger cutting edge to be biased against the inside of said stator tubeside wall.
 31. A cutting tip as claimed in claim 30 including anadditional cutting edge extending along the other of said finger sideedges and biased against the inside of said stator tube side wall.
 32. Acutting tip as claimed in claim 31 wherein said finger cutting edges arestraight.
 33. A cutting tip as claimed in claim 31 wherein said fingercutting edges are parallel to the cutting tip axis.
 34. A cutting tip asclaimed in claim 1 wherein said rotor includes a fluid passagetherethrough.
 35. A cutting tip as claimed in claim 8 wherein said rotorbody includes a fluid passage therethrough.
 36. A cutting tip as claimedin claim 24 wherein said rotor body includes a fluid passagetherethrough.